/Engine/Plugins/Experimental/PCG/Source/PCG/Public/InstanceDataPackers/PCGInstanceDataPackerBase.h
Build a PackedCustomData by processing each attribute in order for each point in the InstanceList
void PackCustomDataFromAttributes ( const [FPCGMeshInstanceList](API\Plugins\PCG\MeshSelectors\FPCGMeshInstanceList) & InstanceList, const [TArray](API\Runtime\Core\Containers\TArray)< const [FPCGMetadataAttributeBase](API\Plugins\PCG\Metadata\FPCGMetadataAttributeBase) * > & Attributes, [FPCGPackedCustomData](API\Plugins\PCG\InstanceDataPackers\FPCGPackedCustomData) & OutPackedCustomData ) const